Log-antilog circuit and method for producing an up-converted and amplified transmission signal

ABSTRACT

According to one exemplary embodiment, a method for producing an up-converted and amplified transmission signal comprises performing a logarithmic transformation of an input transmission signal to form a logarithmically transformed transmission signal, adding the logarithmically transformed transmission signal to a logarithmic local oscillator signal to form a sum signal, and performing an antilogarithmic transformation of the sum signal to produce the up-converted and amplified transmission signal. In one embodiment, a log-antilog circuit for producing an up-converted and an amplified transmission signal comprises a transmission log block configured to receive an input transmission signal and to provide a logarithmically transformed transmission signal as a transmission log block output, and an antilog block coupled to the transmission log block. The antilog block is configured to receive a sum signal of the transmission log block output and a logarithmic local oscillator signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally in the field of electronic circuitsand systems. More specifically, the present invention is in the field ofelectronic communications circuits and systems.

2. Background Art

Mixers are typically used in transmitting systems to, for example,up-convert an input baseband or intermediate frequency (IF) signal priorto transmission. In a conventional mixing circuit, the mixer itself maybe paired with a power amplifier. In that configuration the mixer outputmay be fed into a discrete power amplifier to impart a desirabletransmission power level to the up-converted transmission signal. As isknown in the art, however, the performance of power amplifiers involvesa trade-off between efficiency and the linear response of the amplifier,where improvement in one characteristic results in an undesirabledeterioration of the other.

The consequences of the irreconcilability of linearity and efficiency ina power amplifier has significant implications for mobile communicationdevices utilizing a transmitting system, for example, as part of atransceiver. Because mobile communication devices, such as mobiletelephones, typically rely on a battery for power, inefficiency in apower amplifier undesirably shortens battery life. Utilizing a highefficiency power amplifier, on the other hand, while advantageouslyenhancing battery life, may, due to its reduced linearity, lead toundesirable transmission anomalies, and in extreme cases may result inunintended transmission at frequencies not authorized for public use bythe Federal Communication Commission (FCC).

Thus, there is a need in the art for a solution capable of compensatingfor the performance limitations of a conventional transmitter, thatenables up-conversion and amplification of a transmission signal whileadvantageously providing improved linearity and conserving operationalpower.

SUMMARY OF THE INVENTION

A log-antilog circuit and method for producing an up-converted andamplified transmission signal, substantially as shown in and/ordescribed in connection with at least one of the figures, and as setforth more completely in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a conventional system for up-converting andamplifying a transmission signal.

FIG. 2 is a block diagram showing a log-antilog circuit for producing anup-converted and amplified transmission signal, according to oneembodiment of the present invention.

FIG. 3 is a flowchart of a method for producing an up-converted andamplified transmission signal, according to one embodiment of thepresent invention.

FIG. 4A shows a block diagram of an exemplary transmission log block foruse with a digital input transmission signal, according to oneembodiment of the present invention.

FIG. 4B is a graph showing an exemplary logarithmic transfer functionproduced by the transmission log block embodiment of FIG. 4A.

FIG. 5A shows an exemplary antilog transform circuit suitable for use inthe antilog block of FIG. 2, according to one embodiment of the presentinvention.

FIG. 5B is a graph showing an exemplary antilogarithmic transferfunction produced by the antilog transform circuit of FIG. 5A.

FIG. 5C is a graph showing an exemplary input signal to the antilogtransform circuit of FIG. 5A.

FIG. 5D is a graph showing an exemplary antilogarithmic transformationof the signal of FIG. 5C.

FIG. 6 shows an exemplary antilog transform circuit suitable for use inthe antilog block of FIG. 2, according to another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a log-antilog circuit and methodfor producing an up-converted and amplified transmission signal.Although the invention is described with respect to specificembodiments, the principles of the invention, as defined by the claimsappended herein, can obviously be applied beyond the specificallydescribed embodiments of the invention described herein. Moreover, inthe description of the present invention, certain details have been leftout in order to not obscure the inventive aspects of the invention. Thedetails left out are within the knowledge of a person of ordinary skillin the art.

The drawings in the present application and their accompanying detaileddescription are directed to merely exemplary embodiments of theinvention. To maintain brevity, other embodiments of the invention,which use the principles of the present invention are not specificallydescribed in the present application and are not specificallyillustrated by the present drawings.

FIG. 1 is a block diagram of a conventional system for up-converting andamplifying a transmission signal. FIG. 1 shows transmitting system 100comprising antenna 102, local oscillator 104 providing local oscillatorsignal 106, and mixer circuit 110. Also shown in FIG. 1 are mixercircuit components including power amplifier (PA) 112 and mixer 114. Inaddition, FIG. 1 includes input transmission signal 116, being providedas an input to mixer circuit 110, mixer output 118, and mixer circuitoutput signal 120. Additional elements comprised by transmitting system100 are not shown in FIG. 1 for purposes of clarity and economy ofpresentation. Transmitting system 100 may be utilized in a transmittersupporting cellular telephone communication, or a mobile or stationarytransmitter operating at radio frequency (RF), for example.

In a conventional approach to implementing a transmitting system, suchas transmitting system 100 in FIG. 1, mixer circuit 110 is typicallyutilized to up-convert input transmission signal 116 from baseband or anintermediate frequency (IF), to a transmit frequency such as RF, and toprovide the up-converted transmission signal as mixer circuit outputsignal 120. Up-conversion of input transmission signal 116 isfacilitated by amplification of mixer output 118 by PA 112. Theup-converted and amplified transmission signal is provided as mixercircuit output signal 120, whereupon it may undergo additional signalprocessing steps, for example, highpass filtering, before being fed toantenna 102 for transmission.

Ideally, the performance of PA 112 would be optimized to balance thelinearity requirements imposed by transmitting system 100 withefficiency needs corresponding to available system power. In someimplementations, however, in particular where operating power isprovided by a modular power supply such as a battery, and transmissionpower requirements are high, those competing interests may be nearlyirreconcilable using a conventional transmitting system. Implementationof a conventional transmitting system, such as transmitting system 100,in a battery operated mobile communication device transmitting at aremote distance from a communications base station, for example, mayhave undesirable consequences. As previously described, thoseundesirable consequences may include premature depletion of batterypower, the production of spurious or anomalous transmission signals, orproblems related to both those drawbacks associated with conventionaltransmitting systems.

FIG. 2 is a block diagram showing a log-antilog circuit for producing anup-converted and amplified transmission signal, according to oneembodiment of the present invention, capable of overcoming the drawbacksassociated with the conventional implementation described previously inrelation to FIG. 1. FIG. 2 shows transmitting system 200 comprisingantenna 202, and local oscillator 204 providing local oscillator signal206, corresponding respectively to receiving system 100 comprisingantenna 102, and local oscillator 104 providing local oscillator signal106, in FIG. 1.

FIG. 2 also includes log-antilog circuit 210, which replaces theconventional implementation of mixer circuit 110 shown in FIG. 1.Log-antilog circuit 210 comprises transmission log block 232, localoscillator log block 234, adder 236, and antilog block 238, which,collectively, replace PA 112 and mixer 114 of mixer circuit 110, inFIG. 1. Transmission log block 232, in FIG. 2, is shown to includelookup table 252 and digital-to-analog converter (DAC) 254. Also presentin FIG. 2 are input transmission signal 216, and log-antilog circuitoutput signal 220 being fed to antenna 202, corresponding respectivelyto input transmission signal 116 and mixer circuit output signal 120, inFIG. 1. Moreover, FIG. 2 shows logarithmically transformed transmissionsignal 242, logarithmic local oscillator signal 244, and sum signal 246,having no analogues in the conventional receiving system shown inFIG. 1. As was the case in FIG. 1, additional elements comprised bytransmitting system 200 are not shown in FIG. 2 for purposes of clarityand brevity.

Transmitting system 200 may be utilized in a transmitter supportingcellular telephone communication, other types of mobile transmittersoperating at RF, or a stationary communication system, for example. Inone embodiment, one or more versions of log-antilog circuit 210 may beutilized in a transceiver, such as an RF transceiver used in a mobilecommunication device. For the purposes of the present discussion, let usassume that the exemplary implementation shown in FIG. 2 is utilized toup-convert and amplify input transmission signal 216 in an RFtransmitter, from either baseband or IF, to a transmit frequency in arange from approximately 0.8 GHz to approximately 2.1 GHz.

The operation of log-antilog circuit 210 in FIG. 2 is further explainedin combination with FIG. 3, which shows flowchart 300 describing thesteps, according to one embodiment of the present invention, forproducing an up-converted and amplified transmission signal. Certaindetails and features have been left out of flowchart 300 that areapparent to a person of ordinary skill in the art. For example, a stepmay comprise one or more substeps or may involve specialized equipmentor materials, as known in the art. While steps 310 through 350 indicatedin flowchart 300 are sufficient to describe one embodiment of thepresent invention, other embodiments of the invention may utilize stepsdifferent from those shown in flowchart 300.

Referring to step 310 of flowchart 300, in conjunction with FIG. 2, step310 comprises performing a logarithmic transformation of inputtransmission signal 216 received as an input to transmission log block232, to form a logarithmically transformed transmission signal.Logarithmic transformation of input transmission signal 216 is performedin FIG. 2 by transmission log block 232.

Logarithmic transformation of input transmission signal 216, at step310, permits omission from log-antilog circuit 210, of PA 112 and mixer114, in FIG. 1. This is possible due to the mathematical properties oflogarithmic functions, according to which addition of two logarithmicfunctions corresponds to a sum function containing the product of thearguments of the added functions as a sum function argument, accordingto the following logarithmic identity:log(A ₁)+log(A ₂)=log(A ₁ ×A ₂)  (Equation 1);where A₁ is the argument of the first logarithmic function, A₂ is theargument of the second logarithmic function, and (A₁×A₂) is the argumentof the sum function. Consequently, an operation equivalent to mixing ofa signal logarithmically transformed at step 310 of flowchart 300, maybe achieved through simple addition of that logarithmically transformedcommunication signal with a logarithmic local oscillator signal formedin step 330.

Input transmission signal 216 in the present embodiment shown in FIG. 2is a digital input transmission signal, and transmission log block 232is configured to form a logarithmic transformation of digital inputtransmission signal 216. However, in a different embodiment, an analoginput transmission signal could be used, where log block 232 would bereplaced with an appropriate transmission log block. Because, as isknown in the art, it is impracticable to provide local oscillator signal206 as a digital signal at RF, however, in embodiments in which inputtransmission signal 216 is received as a digital input transmissionsignal, DAC 254 may be implemented to convert the logarithmicallytransformed signal from a digital signal to an analog signal in optionalstep 320. Thus, in the present embodiment, input transmission signal 216is represented as a digital input transmission signal that is firstlogarithmically transformed into a digital logarithmically transformedtransmission signal and subsequently converted to an analoglogarithmically transformed transmission signal. In another embodiment,the digital input transmission signal is converted into an analogtransmission signal prior to logarithmic transformation, where atransmission log block other than the presently illustrated transmissionlog block 232 is used to perform the logarithmic transformation of theanalog signal. Regardless of the order of the DAC conversion andlogarithmic transformation, both operations occur prior to the lateradding step 340.

Continuing with step 330 of flowchart 300, step 330 comprises forming alogarithmic local oscillator signal. Formation of a logarithmic localoscillator signal is achieved in log-antilog circuit 210 of FIG. 2 bylogarithmic transformation of local oscillator signal 206 by localoscillator log block 234. In another embodiment, log-antilog circuit 210may be provided with a logarithmic local oscillator signal by alogarithmic local oscillator signal generator (not shown in FIG. 2), inwhich case log-antilog circuit 210 would not require local oscillatorlog block 234.

Proceeding with step 340 of flowchart 300, step 340 comprises addinglogarithmically transformed transmission signal 242 and logarithmiclocal oscillator signal 244 to form sum signal 246. In FIG. 2, step 340is implemented using adder 236. Although the embodiment of FIG. 2includes adder 236, in one embodiment logarithmically transformedtransmission signal 242 and logarithmic local oscillator signal 244 takethe form of current signals, so that adding those signals may beaccomplished by merely passing them into a common circuit node couplingthe outputs of transmission log block 232 and local oscillator log block234. In that embodiment, adder 236 can be omitted from log-antilogcircuit 210.

Referring to step 350 of flowchart 300, step 350 comprises performing anantilogarithmic transformation of the sum signal formed in step 340 toproduce the up-converted and amplified transmission signal. In FIG. 2,antilog transformation of sum signal 246 is performed by antilog block238. As described previously, sum signal 246 corresponds to alogarithmic signal having, as its argument, the product of inputtransmission signal 216 and local oscillator signal 206. Antilogarithmictransformation of sum signal 246 results in the multiplied, or mixed,signal products of input transmission signal 216 and local oscillatorsignal 206 emerging as log-antilog circuit output signal 220, includinga desired up-converted and amplified transmission signal which may beprovided to antenna 202 for transmission. It is noted that although thepresent embodiment shows log-antilog circuit output signal 220 being fedto antenna 202, in another exemplary implementation, log-antilog circuitoutput signal 220 may be provided to another transmission medium, suchas a communication cable, for instance.

Moving on to FIGS. 4A and 4B, FIG. 4A shows a block diagram of anexemplary transmission log block for use with a digital inputtransmission signal, according to one embodiment of the presentinvention. In FIG. 4A, transmission log block 432 receiving inputtransmission signal 416 as an input and providing logarithmicallytransformed transmission signal 442 as an output, corresponds totransmission log block 232 receiving input transmission signal 216 andproviding logarithmically transformed transmission signal 242, in FIG.2. As further shown in FIG. 4A, transmission log block 432 compriseslookup table 452 and DAC 454, corresponding respectively to lookup table252 and DAC 254, in FIG. 2.

In the embodiment of FIG. 4A, input transmission signal 416 is suppliedas a digital input transmission signal at baseband or IF. Logarithmictransformation of the digital input transmission signal may be performedby utilizing lookup table 452. For example, as shown in FIG. 4A, wherean input digital signal comprises a 16-bit signal, a lookup tableincluding 2¹⁶ lines is capable of matching each 16-bit input to a 16-bitlogarithmically transformed output on a one-to-one basis. As a result,lookup table 452 can be utilized to provide a digital logarithmicallytransformed transmission signal in response to transmission log block432 receiving a digital input as input transmission signal 416.Subsequent conversion of the digital signal provided by lookup table452, by means of DAC 454, as is known in the art, provides an analogsignal as logarithmically transformed transmission signal 442.

Although in the embodiment of FIGS. 2 and 4A, respective transmissionlog blocks 232 and 432 utilize a lookup table to perform logarithmictransformation of a digital input transmission signal, in otherembodiments, other suitable techniques may be used to achieve the signaltransformation, such as implementation of a discrete transformalgorithm, for example. Moreover, although the present exemplaryembodiment shows lookup table 452 configured to transform a 16-bitdigital input signal, in other embodiments, lookup table 452 may beimplemented so as to transform digital signals comprising more or fewerbits. Thus, in other embodiments, lookup table 452 may comprise more orfewer than 2¹⁶ lines.

As previously explained, input transmission signal 216, in FIG. 2, canbe an analog signal as well as a digital signal. When input transmissionsignal 216 is an analog signal, transmission log block 232 will not beimplemented with lookup table 252 and DAC 254. Exemplary implementationsof a log block for logarithmic transformation of an analog transmissionsignal include, for example, a multi-stage amplifier or an anti-paralleldiode pair configuration. These examples, i.e. a multi-stage amplifierand an anti-parallel diode pair configuration, are described on page 14,line 13 through page 15, line 19, and page 18, line 8 through page 19,line 4, of co-pending patent application Ser. No. 11/975,209, filed onOct. 17, 2007. That co-pending application is hereby incorporated fullyby reference into the present application. It is noted that theaforementioned exemplary log blocks are equally suitable forimplementation as transmission log block 232, in FIG. 2 of the presentapplication, when input transmission signal 216 is an analog signal, andas local oscillator log block 234, to perform logarithmic transformationof local oscillator signal 206.

FIG. 4B is a graph showing an exemplary logarithmic transfer functionproduced by the transmission log block embodiment of FIG. 4A. Graph 460,in FIG. 4B, shows an exemplary output signal (I_(OUT)), as a function ofan input signal (I_(IN)). It is noted that although in the presentembodiment input signal I_(IN) and output signal I_(OUT) are representedas current signals, in other embodiments, corresponding input and outputsignals may take the form of voltage signals, for example. Input signalI_(IN), shown on the x-axis of graph 460, corresponds to inputtransmission signals 216 and 416, in FIGS. 2 and 4A, respectively, whileI_(OUT), shown on the y-axis of graph 460, corresponds tologarithmically transformed transmission signals 242 and 442, in thoserespective figures. The performance of transmission log block 232 over arange of input signal strengths is shown by log transfer curve 462.

Log transfer curve 462 may be seen to correspond to the exemplarymathematical transfer function given by:y=signum(x)[log(|x|+1)]  (Equation 2)As is shown by graph 460 and Equation 2, passage of input signal I_(IN)into transmission log block 232 results in an output signal I_(OUT) thatis a logarithmic function of the input, i.e., output signal I_(OUT) is alogarithmic transformation of input signal I_(IN). Implementation of alocal oscillator log block 234, in FIG. 2, produces a similarlogarithmic transformation of local oscillator signal 206, resulting information of logarithmic local oscillator signal 244. In the embodimentof FIG. 2, the logarithmic transformations produced by transmission logblock 232 and local oscillator log block 234 enable addition oflogarithmically transformed transmission signal 242 and logarithmiclocal oscillator signal 244 according to Equation 1.

FIG. 5A shows an exemplary antilog transform circuit suitable for use inthe antilog block shown in FIG. 2, according to one embodiment of thepresent invention. In FIG. 5A, antilog block 538 receiving sum signal546 as an input and providing log-antilog circuit output signal 520 asan output, corresponds to antilog block 238 receiving sum signal 246 andproviding log-antilog circuit output signal 220, in FIG. 2. As shown inFIG. 5A, antilog block 538 comprises antilog transform circuit 550,which includes a multi-stage amplifier comprising substantiallyidentical amplifiers 552 a, 552 b, and 552 c in series. Although thepresent exemplary embodiment shows the multi-stage amplifier of antilogtransform circuit 550 having three substantially identical stages, inother embodiments more stages may be present.

In the embodiment of FIG. 5A, sum signal 546 is supplied as a currentinput I_(IN) formed from additive combination of logarithmicallytransformed transmission signal 242 and logarithmic local oscillator.Successive amplifications of periodic current input I_(IN), performed byamplifiers 552 a, 552 b, and 552 c, transform sum signal 546 intolog-antilog circuit output signal 520, which comprises the up-convertedand amplified transmission signal originally delivered to log-antilogcircuit 210, in FIG. 2, as baseband or IF input transmission signal 216.

It is noted that logarithmic local oscillator signal 244 is provided asa periodic function having a frequency corresponding to local oscillatorsignal 206. Logarithmically transformed transmission signal 242 may besimilarly periodic, due either to periodicity present in an analog inputtransmission signal corresponding to input transmission signal 216, orto a periodicity imposed on a digital logarithmically transformedtransmission signal by DAC 254. As a result, sum signal 246 may bereceived as input to antilog block 538 as a periodic function (furthershown in FIG. 5C). The up-converted and amplified transmission signalappearing as log-antilog circuit output signal 520, may then be providedas sinusoidal current output I_(OUT) (further shown in subsequent FIG.5D).

FIG. 5B is a graph showing an exemplary antilogarithmic transferfunction provided by antilog transform circuit 550 of FIG. 5A. Graph570, in FIG. 5B, shows an exemplary output signal (I_(OUT)), as afunction of an input signal (I_(IN)). Input signal I_(IN), shown on thex-axis of graph 560, corresponds to sum signals 246 and 546, in FIGS. 2and 5A, respectively, while I_(OUT), shown on the y-axis of graph 560,corresponds to log-antilog circuit output signals 220 and 520, in thoserespective figures. The performance of antilog transform circuit 550over a range of input signal strengths is shown by antilog transfercurve 572.

FIG. 5C is a graph showing an exemplary input sum signal to antilogtransform circuit 550 of FIG. 5A. Comparison of FIG. 5C with FIG. 5D,which is a graph showing an exemplary antilogarithmic transformation ofthe input sum signal of FIG. 5C, reveals the result of passing aperiodic logarithmic input signal through an antilog transform circuithaving a performance curve similar to that of antilog transfer curve572, in FIG. 5B. Graph 580, in FIG. 5C shows the amplitude of sum signal546 as a function of time. Antilogarithmic transformation of sum signal546, in FIG. 5C, by antilog transform circuit 550 having antilogtransfer curve 572, shown in FIGS. 5A and 5B, respectively, produceslog-antilog circuit output signal 520, expressed as a function of timein graph 590, of FIG. 5D. As shown by FIGS. 5C and 5D, antilogarithmictransformation of periodic sum signal 546 produces an amplified andsubstantially sinusoidal output signal having substantially the samefrequency as periodic input sum signal 546.

Thus, implementation of a transmitting system utilizing log-antilogcircuit 210 of FIG. 2, in place of conventional mixer circuit 110, inFIG. 1, advantageously produces an up-converted and amplifiedtransmission signal without recourse to PA 112 or conventional mixer114. In an alternative implementation, as part of another embodiment ofthe present invention, the output of antilog block 238, in FIG. 2, maybe further amplified by means of an optional power amplifier. However,even where an optional power amplifier is utilized in conjunction withthe exemplary transmission log blocks and antilog blocks disclosedherein, the amplification, linearity, and efficiency demands placed onthat optional power amplifier can be significantly relaxed, compared toconventional implementations, due to the amplification provided bylog-antilog circuit 210. In effect, the present invention enableselimination of PA 112 entirely, or, alternatively, use of a lower powerPA capable of providing optimal linearity without producing the powerdrain on an operational power supply seen in conventional mixer circuitimplementations.

FIG. 6 shows an exemplary antilog transform circuit suitable for use inthe antilog block shown in FIG. 2, according to another embodiment ofthe present invention. In FIG. 6, antilog block 638 receiving sum signal646 as an input and providing log-antilog circuit output signal 620 asan output, corresponds to antilog block 238 receiving sum signal 246 andproviding log-antilog circuit output signal 220, in FIG. 2. As shown inFIG. 6, antilog block 638 comprises antilog transform circuit 660, whichincludes an anti-parallel pair of substantially identical diodes 662 aand 662 b. As in FIG. 5A, in the embodiment of FIG. 6, log-antilogcircuit output signal 620 is provided as a current output. Unlike theprevious embodiment, however, antilog transform circuit 660 receives sumsignal 646 as a voltage input.

In its various embodiments, the present invention's log-antilog circuitand method for producing an up-converted and amplified transmissionsignal, can be utilized in a transmitting system in, for example, awireless communications device, a mobile telephone, a Bluetooth enableddevice, a computer, an RF transceiver, a personal digital assistant(PDA), or in any other kind of system, device, component or moduleutilized as a transmitter in modern electronics applications.

By introducing a log-antilog circuit and method for producing anup-converted and amplified transmission signal, the present disclosuredescribes a signal processing implementation which advantageouslyutilizes a mathematical property of logarithmic functions to supportadditive signal mixing and amplification. By replacing a conventionalpower amplifier and mixer combination with a log-antilog circuit, thevarious embodiments of the present invention provide linearamplification without incurring the power cost associated with highlylinear transmitter power amplifiers. As a result, the present disclosureenables a solution that compensates for the performance limitations of aconventional transmitter power amplifier by enabling up-conversion andamplification of a transmission signal while advantageously providingimproved linearity and conserving operational power.

From the above description of the invention it is manifest that varioustechniques can be used for implementing the concepts of the presentinvention without departing from its scope. Moreover, while theinvention has been described with specific reference to certainembodiments, a person of ordinary skill in the art would recognize thatchanges can be made in form and detail without departing from the spiritand the scope of the invention. The described embodiments are to beconsidered in all respects as illustrative and not restrictive. Itshould also be understood that the invention is not limited to theparticular embodiments described herein, but is capable of manyrearrangements, modifications, and substitutions without departing fromthe scope of the invention.

Thus, a log-antilog circuit and method for producing an up-converted andamplified transmission signal have been described.

1. A method for producing an up-converted and amplified transmission signal, said method comprising: performing a logarithmic transformation of an input transmission signal to form a logarithmically transformed transmission signal; adding said logarithmically transformed transmission signal to a logarithmic local oscillator signal to form a sum signal; performing an antilogarithmic transformation of said sum signal to produce said up-converted and amplified transmission signal.
 2. The method of claim 1, wherein said input transmission signal comprises a digital input transmission signal.
 3. The method of claim 2, further comprising converting said digital input transmission signal to a digital logarithmically transformed transmission signal.
 4. The method of claim 3, wherein said step of converting said digital input transmission signal to said digital logarithmically transformed transmission signal is performed utilizing a lookup table.
 5. The method of claim 3, further comprising converting said digital logarithmically transformed transmission signal to an analog logarithmically transformed transmission signal to form said logarithmically transformed transmission signal.
 6. The method of claim 1, wherein said up-converted and amplified transmission signal comprises a radio frequency (RF) transmission signal.
 7. The method of claim 1, wherein said step of performing said antilogarithmic transformation of said sum signal is performed utilizing at least one multi-stage amplifier.
 8. The method of claim 1, wherein said step of performing said antilogarithmic transformation of said sum signal is performed utilizing at least one anti-parallel diode pair.
 9. The method of claim 1, wherein said step of performing said logarithmic transformation of said input transmission signal is performed utilizing at least one multi-stage amplifier.
 10. The method of claim 1, wherein said step of performing said logarithmic transformation of said input transmission signal is performed utilizing at least one anti-parallel diode pair.
 11. A log-antilog circuit for producing an up-converted and amplified transmission signal, said log-antilog circuit comprising: a transmission log block configured to receive an input transmission signal and to provide a logarithmically transformed transmission signal as a transmission log block output; an antilog block coupled to said transmission log block, said antilog block configured to receive a sum signal of said transmission log block output and a logarithmic local oscillator signal; said antilog block being configured to output said up-converted and amplified transmission signal.
 12. The log-antilog circuit of claim 11, further comprising an adder for adding said logarithmically transformed transmission signal and said logarithmic local oscillator signal to produce said sum signal.
 13. The log-antilog circuit of claim 11, further comprising a local oscillator log block configured to receive a local oscillator signal as an input and to provide said logarithmic local oscillator signal as an output.
 14. The log-antilog circuit of claim 11, wherein said input transmission signal comprises a digital input transmission signal.
 15. The log-antilog circuit of claim 14, wherein said transmission log block includes a lookup table, said lookup table being utilized to produce a digital logarithmically transformed transmission signal.
 16. The log-antilog circuit of claim 15, wherein said transmission log block includes a digital-to-analog converter configured to receive said digital logarithmically transformed transmission signal as an input and to provide said transmission log block output.
 17. The log-antilog circuit of claim 11, wherein said antilog block comprises at least one multi-stage amplifier.
 18. The log-antilog circuit of claim 11, wherein said antilog block comprises at least one anti-parallel diode pair.
 19. The log-antilog circuit of claim 11, wherein said transmission log block comprises at least one multi-stage amplifier.
 20. The log-antilog circuit of claim 11, wherein said transmission log block comprises at least one anti-parallel diode pair.
 21. The log-antilog circuit of claim 11, utilized as a part of a communication system, said communication system being selected from the group consisting of a wireless communications device, a mobile telephone, a Bluetooth enabled device, a computer, a radio frequency (RF) transceiver, and a personal digital assistant (PDA). 